Japanese four-cylinder engine is so reliable still in production after 25 years • Hacker News Board

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#61

Post by monegator » Thu, Dec 04, 2025, 4:55 PM UTC

pmontra wrote: post #30

That's a series of engines, not a single model. The FIAT FIRE [1] series has been in production for 36 years from 1985 to 2021 and, maybe you wouldn't expect it from FIAT, those engines were reliable. [1] https://en.wikipedia.org/wiki/Fully_Integrated_Robotised_Eng...

Came here just to rant about the FIRE and the Firefly. The Multijet was also extremely reliable.

Instead, they were tossed aside to promote whatever garbage came out of citroen design centers, i guess to achieve the destruction of stellantis. (except in south america, they still get to use the Firefly)

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#62

Post by [deleted] » Thu, Dec 04, 2025, 4:56 PM UTC

skywal_l wrote: post #49

pmontra wrote: post #30

That's a series of engines, not a single model. The FIAT FIRE [1] series has been in production for 36 years from 1985 to 2021 and, maybe you wouldn't expect it from FIAT, those engines were reliable. [1] https://en.wikipedia.org/wiki/Fully_Integrated_Robotised_Eng...

I counter you with a Cleon engine[0] with 42 years. ;) But in the end an engine can be reliable but still be an environmental liability. [0]: https://en.wikipedia.org/wiki/Renault_Cl%C3%A9on-Fonte_engin...

[deleted]

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#63

Post by Grosvenor » Thu, Dec 04, 2025, 4:57 PM UTC

skywal_l wrote: post #49

pmontra wrote: post #30

That's a series of engines, not a single model. The FIAT FIRE [1] series has been in production for 36 years from 1985 to 2021 and, maybe you wouldn't expect it from FIAT, those engines were reliable. [1] https://en.wikipedia.org/wiki/Fully_Integrated_Robotised_Eng...

I counter you with a Cleon engine[0] with 42 years. ;) But in the end an engine can be reliable but still be an environmental liability. [0]: https://en.wikipedia.org/wiki/Renault_Cl%C3%A9on-Fonte_engin...

I’ll counter with the jaguar xk engine in production for 43 years.

https://en.wikipedia.org/wiki/Jaguar_XK_engine

I assume the American s will be by with a pushrod v8 soon.

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#64

Post by bluGill » Thu, Dec 04, 2025, 4:57 PM UTC

Aurornis wrote: post #53

The headline isn’t really true. The K series of engines has been in production for 25 years but it has been redesigned along the way. The article mentions this further down: > The K20C is Honda's current-generation of the K-Series range, upgraded to deliver strong real-world efficiency and long-term reliability across the Honda and Acura catalogs. It's also a redesign that meets stricter global emissions rules and ti…

What criteria should we use to decide if redesigns are significant enough to not claim it is the same engine?

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#65

Post by TheCondor » Thu, Dec 04, 2025, 4:58 PM UTC

pmontra wrote: post #30

That's a series of engines, not a single model. The FIAT FIRE [1] series has been in production for 36 years from 1985 to 2021 and, maybe you wouldn't expect it from FIAT, those engines were reliable. [1] https://en.wikipedia.org/wiki/Fully_Integrated_Robotised_Eng...

The Jag XK platform had 45+ year run. I'd bet that as long as the 911 is made, it'll have an inline 6 and to someone's thinking it will be the same platform as the air-cooled version from 1964.

Engine architectures tend to last unless they are bad. They can do a lot on one also, the Toyota GR platform started out as a fairly vanilla V-6 but it has variations with GDI and variations with turbochargers and has been used a lot of different vehicles. A lot of different variations with different levels of compressions and such. It's basically the block and cylinders configuration.

I'll shout out the K-series though, it's a shockingly good platform. Lots of little details have been thought through, it's relatively simple, inexpensive and reliable and maybe one of the easiest engines to work on. If you were new to cars and wanted to start wrenching, the K-series is a pretty good place to start. It can take boost and make power and has lots of aftermarket support. I know civics aren't everyones cup of tea and it's not a big V-8, but I've yet to meet an engineer that isn't at least slightly impressed by the k-series.

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#66

Post by EugenioPerea » Thu, Dec 04, 2025, 5:02 PM UTC

TheCondor wrote: post #65

pmontra wrote: post #30

That's a series of engines, not a single model. The FIAT FIRE [1] series has been in production for 36 years from 1985 to 2021 and, maybe you wouldn't expect it from FIAT, those engines were reliable. [1] https://en.wikipedia.org/wiki/Fully_Integrated_Robotised_Eng...

The Jag XK platform had 45+ year run. I'd bet that as long as the 911 is made, it'll have an inline 6 and to someone's thinking it will be the same platform as the air-cooled version from 1964. Engine architectures tend to last unless they are bad. They can do a lot on one also, the Toyota GR platform started out as a fairly vanilla V-6 but it has variations with GDI and variations with turbochargers and has been use…

The 911 is a flat-six, but I agree with your point wholeheartedly.

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#67

Post by pixl97 » Thu, Dec 04, 2025, 5:02 PM UTC

bluGill wrote: post #64

Aurornis wrote: post #53

The headline isn’t really true. The K series of engines has been in production for 25 years but it has been redesigned along the way. The article mentions this further down: > The K20C is Honda's current-generation of the K-Series range, upgraded to deliver strong real-world efficiency and long-term reliability across the Honda and Acura catalogs. It's also a redesign that meets stricter global emissions rules and ti…

What criteria should we use to decide if redesigns are significant enough to not claim it is the same engine?

Parts compatibility?

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#68

Post by jeffbee » Thu, Dec 04, 2025, 5:03 PM UTC

officeplant wrote: post #56

jeffbee wrote: post #28

Earlier quoted context omitted.

Perhaps that's what's remarkable about these? They had architectures that could meet 2025 emissions standards, 25 years ago. That said the Honda "L" series engines are just as long-lived and are the even more efficient variety.

My favorite fact I used to tell people when I owned a 2008 Honda Fit was that parts of the L-Series engines was from Honda Powersport's Boat Motor lines. (the crankshaft if memory isn't failing me)

They should do more cross-over technology. Why do they make a motorcycle with a 1.8l flat 6 engine that shares the 73mmx73mm cylinder format of the early L-series car engine, but they can't bring an engine like that to cars? It would be smooth as hell.

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#69

Post by bmurphy1976 » Thu, Dec 04, 2025, 5:04 PM UTC

I strongly suspected it was going to be a Honda before even clicking the link. I traded in my RSX-s many years ago for Cherokee because kids. I miss that car, that was a lovely engine even though the low-end torque was a bit anemic.

Re: Japanese four-cylinder engine is so reliable still in production after 25 years

#70

Post by bluGill » Thu, Dec 04, 2025, 5:06 PM UTC

potato3732842 wrote: post #27

25yr is "meeting expectations" for any mass market[1] engine designed after about the mid 1970s or so. A design that is both not fundamentally flawed in some way and cutting edge enough for its time to not quickly rendered obsolete the steady increase in expectations should go far longer. A design that is "ok" and cutting edge will probably go 20-30yr. A design that is behind the times, and very good (easier to not m…

Needs a million upvotes. It costs a large pile of money to design an all-new engine from the ground up that meets modern emissions and is reliable is service for hundreds of thousands of miles. You should be thinking billions of dollars. They only way to make this affordable is to amortize that cost over many many cars of many many years. Sure you will tweak the design here and there for various reasons, but the initial investment to get the first car to a customer is too high to dare start again anytime soon.

Of course with electric cars obviously coming it is questionable if any engine is worth starting today. There isn't much worth doing that a minor tweak to an existing design cannot do - and even if there is something it is questionable if engines will be sold long enough to be worth it. (at least for cars - if you target boats or construction equipment or such maybe - though you will note smaller boats typically just take an existing engine and tweak it because there are not enough small boats sold to be worth a new design)